Secure caps for containers of various substances are encountered frequently. Automotive and truck fuel tanks employ locking caps to prevent theft of gasoline and diesel fuel. Various designs for child-proofing medicine bottles and cleaning supplies rely on strength and complex manipulation to keep potent medicines and corrosive chemicals out of the mouths of babes.
U.S. Pat. No. 4,796,768 to Stuckey discloses a locking mechanism for a cap based on a clutching mechanism and using a keyed or combination lock.
U.S. Pat. No. 4,848,621 to Radliff discloses a cap for a fuel container in which a key may be hidden.
U.S. Pat. No. 5,212,971 to Yoon et al. discloses a “push button combination lock” to secure a fuel tank.
U.S. Pat. No. 5,317,796 to Hunter discloses child resistant packaging which employs combinations of twists to deter children while still making the contents accessible to adults. U.S. Pat. No. 5,351,845, also to Hunter, discloses another combination style twist-off cap.
U.S. Pat. No. 6,059,132 to Benjamin is directed to a combination lock cap for a threaded bottle.
U.S. Pat. No. 6,059,135 to James et al. is directed to a compartmentalized “lunch pail” with a combination lock in the lid and sliding bolt type latching system.
U.S. Pat. No. 6,786,346 to Gurnard et al. is directed to a locking cap for a drinking glass using a wire to pull a castellated skirt portion under a lip and to release the wire when a correct combination is put into the wire latching area.
The prior are safety caps are complicated and are not readily adapted to common sized containers such as the ubiquitous amber bottles or vials identified with pharmacies prescription filling or other common bottles for household cleaners.